U.S. patent application number 14/101829 was filed with the patent office on 2014-06-26 for cooking oils and food products comprising estolides.
This patent application is currently assigned to BIOSYNTHETIC TECHNOLOGIES, LLC. The applicant listed for this patent is BIOSYNTHETIC TECHNOLOGIES, LLC. Invention is credited to Jeremy FOREST.
Application Number | 20140178547 14/101829 |
Document ID | / |
Family ID | 50974935 |
Filed Date | 2014-06-26 |
United States Patent
Application |
20140178547 |
Kind Code |
A1 |
FOREST; Jeremy |
June 26, 2014 |
COOKING OILS AND FOOD PRODUCTS COMPRISING ESTOLIDES
Abstract
Cooking and frying oils comprising estolide compounds are
described. Also described are methods of making food products
comprising cooking or otherwise preparing at least one article of
food with a composition comprising at least one estolide
compound.
Inventors: |
FOREST; Jeremy; (Honolulu,
HI) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
BIOSYNTHETIC TECHNOLOGIES, LLC |
Irvine |
CA |
US |
|
|
Assignee: |
BIOSYNTHETIC TECHNOLOGIES,
LLC
Irvine
CA
|
Family ID: |
50974935 |
Appl. No.: |
14/101829 |
Filed: |
December 10, 2013 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
61745400 |
Dec 21, 2012 |
|
|
|
Current U.S.
Class: |
426/438 |
Current CPC
Class: |
A23L 5/11 20160801; A23L
19/18 20160801; A23G 3/40 20130101; A23D 7/0053 20130101 |
Class at
Publication: |
426/438 |
International
Class: |
A23L 1/01 20060101
A23L001/01 |
Claims
1. A method of preparing a food product, comprising cooking an
article of food in a composition comprising at least one estolide
compound selected from compounds of Formula I: ##STR00010## wherein
x is, independently for each occurrence, an integer selected from 0
to 20; y is, independently for each occurrence, an integer selected
from 0 to 20; n is an integer greater than or equal to 0; R.sub.1
is an optionally substituted alkyl that is saturated or
unsaturated, and branched or unbranched; and R.sub.2 is selected
from hydrogen and an optionally substituted alkyl that is saturated
or unsaturated, and branched or unbranched, wherein each fatty acid
chain residue of said at least one estolide compound is
independently optionally substituted.
2. The method according to claim 1, wherein x is, independently for
each occurrence, an integer selected from 1 to 10; y is,
independently for each occurrence, an integer selected from 1 to
10; n is an integer selected from 0 to 8; R.sub.1 is an optionally
substituted C.sub.1 to C.sub.22 alkyl that is saturated or
unsaturated, and branched or unbranched; and R.sub.2 is an
optionally substituted C.sub.1 to C.sub.22 alkyl that is saturated
or unsaturated, and branched or unbranched, wherein each fatty acid
chain residue is unsubstituted.
3. The method according to any one of claims 1 and 2, wherein x+y
is, independently for each chain, an integer selected from 13 to
15; and n is an integer selected from 0 to 6.
4. The method according to any one of claims 1-3, wherein R.sub.2
is an unsubstituted alkyl that is saturated or unsaturated, and
branched or unbranched
5. The food product according to any one of claims 1-4, wherein
R.sub.2 is a branched or unbranched C.sub.1 to C.sub.20 alkyl that
is saturated or unsaturated.
6. The method according to claim 5, wherein R.sub.2 is selected
from methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl,
nonyl, decanyl, undecanyl, dodecanyl, tridecanyl, tetradecanyl,
pentadecanyl, hexadecanyl, heptadecanyl, octadecanyl, nonadecanyl,
and icosanyl, which are saturated or unsaturated and branched or
unbranched.
7. The method according to claim 5, wherein R.sub.2 is selected
from C.sub.6 to C.sub.12 alkyl.
8. The method according to claim 7, wherein R.sub.2 is
2-ethylhexyl.
9. The method according to any one of claims 1-8, wherein R.sub.1
is a branched or unbranched C.sub.1 to C.sub.20 alkyl that is
saturated or unsaturated.
10. The method according to claim 9, wherein R.sub.1 is selected
from methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl,
nonyl, decanyl, undecanyl, dodecanyl, tridecanyl, tetradecanyl,
pentadecanyl, hexadecanyl, heptadecanyl, octadecanyl, nonadecanyl,
and icosanyl, which are saturated or unsaturated and branched or
unbranched.
11. The method according to claim 9, wherein R.sub.1 is selected
from unsubstituted C.sub.7 to C.sub.17 alkyl that is unbranched and
saturated or unsaturated.
12. The method according to claim 11, wherein R.sub.1 is selected
from C.sub.13 to C.sub.17 alkyl that is unsubstituted, unbranched,
and saturated or unsaturated.
13. The method according to claim 11, wherein R.sub.1 is selected
from saturated C.sub.7 alkyl, saturated C.sub.9 alkyl, saturated
C.sub.11 alkyl, saturated C.sub.13 alkyl, saturated C.sub.15 alkyl,
and saturated or unsaturated C.sub.17 alkyl, which are
unsubstituted and unbranched.
14. The method according to claim 12, wherein R.sub.1 is selected
from saturated C.sub.13 alkyl, saturated C.sub.15 alkyl, and
saturated or unsaturated C.sub.17 alkyl, which are unsubstituted
and unbranched.
15. The method according to any one of claims 1-5, wherein R.sub.1
and R.sub.2 are independently selected from optionally substituted
C.sub.1 to C.sub.18 alkyl that is saturated or unsaturated, and
branched or unbranched.
16. The method according to any one of claims 1-5, wherein R.sub.1
is selected from optionally substituted C.sub.7 to C.sub.17 alkyl
that is saturated or unsaturated, and branched or unbranched; and
R.sub.2 is selected from an optionally substituted C.sub.3 to
C.sub.20 alkyl that is saturated or unsaturated, and branched or
unbranched.
17. The method according to any one of claims 1-16, wherein
composition has an EN selected from an integer or fraction of an
integer that is equal to or less than 2, wherein EN is the average
number of linkages in compounds according to Formula I.
18. The method according to claim 17, wherein said composition has
an EN that is an integer or fraction of an integer selected from 1
to 2, wherein EN is the average number of linkages in compounds
according to Formula I.
19. The method according to any one of claims 1-18, wherein said
composition has a kinematic viscosity equal to or less than 55 cSt
when measured at 40.degree. C.
20. The method according to any one of claims 1-19, wherein said
composition has a pour point equal to or lower than -25.degree.
C.
21. The method according to claim 5, wherein R.sub.2 is ethyl.
22. The method according to any one of claims 1-21, wherein x is,
independently for each occurrence, an integer selected from 7 and
8.
23. The method according to any one of claims 1-22, wherein y is,
independently for each occurrence, an integer selected from 7 and
8.
24. The method according to any one of claims 1-23, wherein said
composition has a kinematic viscosity equal to or less than 10 cSt
when measured at 100.degree. C.
25. A method of preparing a food product, comprising cooking an
article of food in a composition comprising at least one estolide
compound selected from compounds of Formula I, Formula II, and/or
Formula III.
26. The method according to any one of claims 1-25, wherein the
cooking comprises heating the composition to frying temperature,
and contacting the article of food with said composition for a time
sufficient to fry said article of food.
27. The method according to claim 26, wherein the frying
temperature is selected from a range of about 170.degree. C. to
about 190.degree. C.
28. A food product, wherein said food product is prepared by a
process that including cooking an article of food in a composition
comprising at least one estolide compound selected from compounds
of Formula I, Formula II, and/or Formula III.
29. The food product/method according to any of claims 22-25,
wherein the at least one estolide compound is selected from
compounds of Formula I, Formula II, and/or Formula III.
30. A food product containing a composition comprising at least one
estolide compound selected from compounds of Formula I, Formula II,
and/or Formula III.
31. The food product according to claim 30, wherein the composition
comprises a fat substitute.
32. The food product according to any one of claims 30-31, wherein
said composition has an EN that is an integer or fraction of an
integer that is equal to or greater than 2, wherein EN is the
average number of linkages in compounds according to Formula I.
33. The food product according to claim 32, wherein said
composition has an EN that is an integer or fraction of an integer
selected from 3 to 5, wherein EN is the average number of linkages
in compounds according to Formula I.
34. A food product according to any one of claims 30-33, wherein
said composition has a kinematic viscosity equal to or greater than
15 cSt when measured at 100.degree. C.
35. A food product according to any one of claims 30-34, wherein
said composition has a kinematic viscosity equal to or greater than
20 cSt when measured at 100.degree. C.
36. A food product according to any one of claims 30-35, wherein
said composition has a kinematic viscosity of 15 cSt to 35 cSt when
measured at 100.degree. C.
Description
FIELD
[0001] The present disclosure relates to cooking and frying oils
comprising estolide compounds. Also described herein are food
additives comprising one or more estolide compounds.
BACKGROUND
[0002] Cooking and frying oil compositions typically comprise
vegetable oil-based triglycerides. However, the relative hydrolytic
instability of triglyceride molecules diminishes the fry life of
such oils, resulting in the need for more frequent change
intervals. Synthetic estolide compounds present a
hydrolytically-stable alternative to triglycerides that may be
useful in extending the fry life of cooking oil compositions.
Frying/cooking food articles with estolides may also provide
consumers with a healthier alternative to triglyceride-based
oils.
SUMMARY
[0003] Described herein are estolide compounds, estolide-containing
compositions, and methods of making the same. In certain
embodiments, such compounds and/or compositions may be useful as
cooking and frying oils.
[0004] In certain embodiments, the estolides comprise at least one
compound of Formula I:
##STR00001##
[0005] wherein
[0006] x is, independently for each occurrence, an integer selected
from 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, and 10;
[0007] y is, independently for each occurrence, an integer selected
from 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, and 10;
[0008] n is an integer selected from 0, 1, 2, 3, 4, 5, 6, 7, 8, 9,
10, 11, and 12;
[0009] R.sub.1 is an optionally substituted alkyl that is saturated
or unsaturated, and branched or unbranched; and
[0010] R.sub.2 is selected from hydrogen and an optionally
substituted alkyl that is saturated or unsaturated, and branched or
unbranched;
[0011] wherein each fatty acid chain residue of said at least one
compound is independently optionally substituted.
[0012] In certain embodiments, the estolides comprise at least one
compound of Formula II:
##STR00002##
[0013] wherein
[0014] m is an integer equal to or greater than 1;
[0015] n is an integer equal to or greater than 0;
[0016] R.sub.1, independently for each occurrence, is an optionally
substituted alkyl that is saturated or unsaturated, and branched or
unbranched;
[0017] R.sub.2 is selected from hydrogen and optionally substituted
alkyl that is saturated or unsaturated, and branched or unbranched;
and
[0018] R.sub.3 and R.sub.4, independently for each occurrence, are
selected from optionally substituted alkyl that is saturated or
unsaturated, and branched or unbranched.
[0019] In certain embodiments, the estolides comprise at least one
estolide compound of Formula III:
##STR00003##
[0020] wherein
[0021] x is, independently for each occurrence, an integer selected
from 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17,
18, 19, and 20;
[0022] y is, independently for each occurrence, an integer selected
from 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17,
18, 19, and 20;
[0023] n is an integer equal to or greater than 0;
[0024] R.sub.1 is an optionally substituted alkyl that is saturated
or unsaturated, and branched or unbranched; and
[0025] R.sub.2 is selected from hydrogen and an optionally
substituted alkyl that is saturated or unsaturated, and branched or
unbranched,
[0026] wherein each fatty acid chain residue of said at least one
compound is independently optionally substituted.
[0027] A food product is also described. In certain embodiments,
the food product comprises at least one estolide compound. In
certain embodiments, the food product is prepared by a process that
includes cooking an article of food in a composition comprising at
least one estolide compound.
[0028] A method of preparing a food product is also described. In
certain embodiments, the method comprises cooking an article of
food in a composition comprising at least one estolide
compound.
DETAILED DESCRIPTION
[0029] In addition to decreased fry life, the use of
triglyceride-based fry and cooking oils presents several dietary
concerns to mammalian populations, and particularly humans. Dietary
fats/triglycerides are digested into free fatty acids and
monoglycerides, primarily in the small intestine. Enzymes in the
small intestine cleave glycerol esters at the first and third
positions, resulting in free fatty acids which are absorbed into
the body. Accordingly, in an effort to reduce fat consumption and
absorption, there remains a need to develop low-calorie fats or fat
substitutes.
[0030] One approach is to develop low-calorie fat substitutes,
including substitutes for triglyceride-based cooking and frying
oils. In some cases, this may be achieved by altering the structure
of natural triglycerides to retain their conventional properties in
foods, while eliminating their tendency toward hydrolysis and
subsequent absorption during digestion. In certain embodiments,
this is achieved by replacing triglycerides with one or more
estolide compounds. In certain embodiments, the estolide compounds
act as a fat substitute that add no fat, calories, or cholesterol
to the food product.
[0031] As used in the present specification, the following words,
phrases and symbols are generally intended to have the meanings as
set forth below, except to the extent that the context in which
they are used indicates otherwise. The following abbreviations and
terms have the indicated meanings throughout:
[0032] A dash ("--") that is not between two letters or symbols is
used to indicate a point of attachment for a substituent. For
example, --C(O)NH.sub.2 is attached through the carbon atom.
[0033] "Alkoxy" by itself or as part of another substituent refers
to a radical --OR.sup.31 where R.sup.31 is alkyl, cycloalkyl,
cycloalkylalkyl, aryl, or arylalkyl, which can be substituted, as
defined herein. In some embodiments, alkoxy groups have from 1 to 8
carbon atoms. In some embodiments, alkoxy groups have 1, 2, 3, 4,
5, 6, 7, or 8 carbon atoms. Examples of alkoxy groups include, but
are not limited to, methoxy, ethoxy, propoxy, butoxy,
cyclohexyloxy, and the like.
[0034] "Alkyl" by itself or as part of another substituent refers
to a saturated or unsaturated, branched, or straight-chain
monovalent hydrocarbon radical derived by the removal of one
hydrogen atom from a single carbon atom of a parent alkane, alkene,
or alkyne. Examples of alkyl groups include, but are not limited
to, methyl; ethyls such as ethanyl, ethenyl, and ethynyl; propyls
such as propan-1-yl, propan-2-yl, prop-1-en-1-yl, prop-1-en-2-yl,
prop-2-en-1-yl (allyl), prop-1-yn-1-yl, prop-2-yn-1-yl, etc.;
butyls such as butan-1-yl, butan-2-yl, 2-methyl-propan-1-yl,
2-methyl-propan-2-yl, but-1-en-1-yl, but-1-en-2-yl,
2-methyl-prop-1-en-1-yl, but-2-en-1-yl, but-2-en-2-yl,
buta-1,3-dien-1-yl, buta-1,3-dien-2-yl, but-1-yn-1-yl,
but-1-yn-3-yl, but-3-yn-1-yl, etc.; and the like.
[0035] Unless otherwise indicated, the term "alkyl" is specifically
intended to include groups having any degree or level of
saturation, i.e., groups having exclusively single carbon-carbon
bonds, groups having one or more double carbon-carbon bonds, groups
having one or more triple carbon-carbon bonds, and groups having
mixtures of single, double, and triple carbon-carbon bonds. Where a
specific level of saturation is intended, the terms "alkanyl,"
"alkenyl," and "alkynyl" are used. In certain embodiments, an alkyl
group comprises from 1 to 40 carbon atoms, in certain embodiments,
from 1 to 22 or 1 to 18 carbon atoms, in certain embodiments, from
1 to 16 or 1 to 8 carbon atoms, and in certain embodiments from 1
to 6 or 1 to 3 carbon atoms. In certain embodiments, an alkyl group
comprises from 8 to 22 carbon atoms, in certain embodiments, from 8
to 18 or 8 to 16. In some embodiments, the alkyl group comprises
from 3 to 20 or 7 to 17 carbons. In some embodiments, the alkyl
group comprises 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15,
16, 17, 18, 19, 20, 21, or 22 carbon atoms.
[0036] "Aryl" by itself or as part of another substituent refers to
a monovalent aromatic hydrocarbon radical derived by the removal of
one hydrogen atom from a single carbon atom of a parent aromatic
ring system. Aryl encompasses 5- and 6-membered carbocyclic
aromatic rings, for example, benzene; bicyclic ring systems wherein
at least one ring is carbocyclic and aromatic, for example,
naphthalene, indane, and tetralin; and tricyclic ring systems
wherein at least one ring is carbocyclic and aromatic, for example,
fluorene. Aryl encompasses multiple ring systems having at least
one carbocyclic aromatic ring fused to at least one carbocyclic
aromatic ring, cycloalkyl ring, or heterocycloalkyl ring. For
example, aryl includes 5- and 6-membered carbocyclic aromatic rings
fused to a 5- to 7-membered non-aromatic heterocycloalkyl ring
containing one or more heteroatoms chosen from N, O, and S. For
such fused, bicyclic ring systems wherein only one of the rings is
a carbocyclic aromatic ring, the point of attachment may be at the
carbocyclic aromatic ring or the heterocycloalkyl ring. Examples of
aryl groups include, but are not limited to, groups derived from
aceanthrylene, acenaphthylene, acephenanthrylene, anthracene,
azulene, benzene, chrysene, coronene, fluoranthene, fluorene,
hexacene, hexaphene, hexylene, as-indacene, s-indacene, indane,
indene, naphthalene, octacene, octaphene, octalene, ovalene,
penta-2,4-diene, pentacene, pentalene, pentaphene, perylene,
phenalene, phenanthrene, picene, pleiadene, pyrene, pyranthrene,
rubicene, triphenylene, trinaphthalene, and the like. In certain
embodiments, an aryl group can comprise from 5 to 20 carbon atoms,
and in certain embodiments, from 5 to 12 carbon atoms. In certain
embodiments, an aryl group can comprise 5, 6, 7, 8, 9, 10, 11, 12,
13, 14, 15, 16, 17, 18, 19, or 20 carbon atoms. Aryl, however, does
not encompass or overlap in any way with heteroaryl, separately
defined herein. Hence, a multiple ring system in which one or more
carbocyclic aromatic rings is fused to a heterocycloalkyl aromatic
ring, is heteroaryl, not aryl, as defined herein.
[0037] "Arylalkyl" by itself or as part of another substituent
refers to an acyclic alkyl radical in which one of the hydrogen
atoms bonded to a carbon atom, typically a terminal or sp.sup.3
carbon atom, is replaced with an aryl group. Examples of arylalkyl
groups include, but are not limited to, benzyl, 2-phenylethan-1-yl,
2-phenylethen-1-yl, naphthylmethyl, 2-naphthylethan-1-yl,
2-naphthylethen-1-yl, naphthobenzyl, 2-naphthophenylethan-1-yl, and
the like. Where specific alkyl moieties are intended, the
nomenclature arylalkanyl, arylalkenyl, or arylalkynyl is used. In
certain embodiments, an arylalkyl group is C.sub.7-30 arylalkyl,
e.g., the alkanyl, alkenyl, or alkynyl moiety of the arylalkyl
group is C.sub.1-10 and the aryl moiety is C.sub.6-20, and in
certain embodiments, an arylalkyl group is C.sub.7-20 arylalkyl,
e.g., the alkanyl, alkenyl, or alkynyl moiety of the arylalkyl
group is C.sub.1-8 and the aryl moiety is C.sub.6-12.
[0038] Estolide "base oil" and "base stock", unless otherwise
indicated, refer to any composition comprising one or more estolide
compounds. It should be understood that an estolide "base oil" or
"base stock" is not limited to compositions for a particular use,
and may generally refer to compositions comprising one or more
estolides, including mixtures of estolides. Estolide base oils and
base stocks can also include compounds other than estolides.
[0039] The term "catalyst" refers to single chemical species;
physical combinations of chemical species, such as mixtures,
alloys, and the like; and combinations of one or more catalyst
within the same region or location of a reactor or reaction vessel.
Examples of catalyst include, e.g., Lewis acids, Bronsted acids,
and Bismuth catalysts, wherein Lewis acids, Bronsted acids, and
Bismuth catalysts may be single chemical species; physical
combinations of chemical species, such as mixtures, alloys, and the
like; and combinations of one or more catalyst within the same
region or location of a reactor or reaction vessel.
[0040] "Compounds" refers to compounds encompassed by structural
Formula I, II, and III herein and includes any specific compounds
within the formula whose structure is disclosed herein. Compounds
may be identified either by their chemical structure and/or
chemical name. When the chemical structure and chemical name
conflict, the chemical structure is determinative of the identity
of the compound. The compounds described herein may contain one or
more chiral centers and/or double bonds and therefore may exist as
stereoisomers such as double-bond isomers (i.e., geometric
isomers), enantiomers, or diastereomers. Accordingly, any chemical
structures within the scope of the specification depicted, in whole
or in part, with a relative configuration encompass all possible
enantiomers and stereoisomers of the illustrated compounds
including the stereoisomerically pure form (e.g., geometrically
pure, enantiomerically pure, or diastereomerically pure) and
enantiomeric and stereoisomeric mixtures. Enantiomeric and
stereoisomeric mixtures may be resolved into their component
enantiomers or stereoisomers using separation techniques or chiral
synthesis techniques well known to the skilled artisan.
[0041] For the purposes of the present disclosure, "chiral
compounds" are compounds having at least one center of chirality
(i.e. at least one asymmetric atom, in particular at least one
asymmetric C atom), having an axis of chirality, a plane of
chirality or a screw structure. "Achiral compounds" are compounds
which are not chiral.
[0042] Compounds of Formula I, II, and III include, but are not
limited to, optical isomers of compounds of Formula I, II, and III,
racemates thereof, and other mixtures thereof. In such embodiments,
the single enantiomers or diastereomers, i.e., optically active
forms, can be obtained by asymmetric synthesis or by resolution of
the racemates. Resolution of the racemates may be accomplished by,
for example, chromatography, using, for example a chiral
high-pressure liquid chromatography (HPLC) column. However, unless
otherwise stated, it should be assumed that Formula I, II, and III
cover all asymmetric variants of the compounds described herein,
including isomers, racemates, enantiomers, diastereomers, and other
mixtures thereof. In addition, compounds of Formula I, II and III
include Z- and E-forms (e.g., cis- and trans-forms) of compounds
with double bonds. The compounds of Formula I, II, and III may also
exist in several tautomeric forms including the enol form, the keto
form, and mixtures thereof. Accordingly, the chemical structures
depicted herein encompass all possible tautomeric forms of the
illustrated compounds.
[0043] "Cycloalkyl" by itself or as part of another substituent
refers to a saturated or unsaturated cyclic alkyl radical. Where a
specific level of saturation is intended, the nomenclature
"cycloalkanyl" or "cycloalkenyl" is used. Examples of cycloalkyl
groups include, but are not limited to, groups derived from
cyclopropane, cyclobutane, cyclopentane, cyclohexane, and the like.
In certain embodiments, a cycloalkyl group is C.sub.3-15
cycloalkyl, and in certain embodiments, C.sub.3-12 cycloalkyl or
C.sub.5-12 cycloalkyl. In certain embodiments, a cycloalkyl group
is a C.sub.5, C.sub.6, C.sub.7, C.sub.8, C.sub.9, C.sub.10,
C.sub.11, C.sub.12, C.sub.13, C.sub.14, or C.sub.15 cycloalkyl.
[0044] "Cycloalkylalkyl" by itself or as part of another
substituent refers to an acyclic alkyl radical in which one of the
hydrogen atoms bonded to a carbon atom, typically a terminal or
sp.sup.3 carbon atom, is replaced with a cycloalkyl group. Where
specific alkyl moieties are intended, the nomenclature
cycloalkylalkanyl, cycloalkylalkenyl, or cycloalkylalkynyl is used.
In certain embodiments, a cycloalkylalkyl group is C.sub.7-30
cycloalkylalkyl, e.g., the alkanyl, alkenyl, or alkynyl moiety of
the cycloalkylalkyl group is C.sub.1-10 and the cycloalkyl moiety
is C.sub.6-20, and in certain embodiments, a cycloalkylalkyl group
is C.sub.7-20 cycloalkylalkyl, e.g., the alkanyl, alkenyl, or
alkynyl moiety of the cycloalkylalkyl group is C.sub.1-8 and the
cycloalkyl moiety is C.sub.4-20 or C.sub.6-12.
[0045] "Halogen" refers to a fluoro, chloro, bromo, or iodo
group.
[0046] "Heteroaryl" by itself or as part of another substituent
refers to a monovalent heteroaromatic radical derived by the
removal of one hydrogen atom from a single atom of a parent
heteroaromatic ring system. Heteroaryl encompasses multiple ring
systems having at least one aromatic ring fused to at least one
other ring, which can be aromatic or non-aromatic in which at least
one ring atom is a heteroatom. Heteroaryl encompasses 5- to
12-membered aromatic, such as 5- to 7-membered, monocyclic rings
containing one or more, for example, from 1 to 4, or in certain
embodiments, from 1 to 3, heteroatoms chosen from N, O, and S, with
the remaining ring atoms being carbon; and bicyclic
heterocycloalkyl rings containing one or more, for example, from 1
to 4, or in certain embodiments, from 1 to 3, heteroatoms chosen
from N, O, and S, with the remaining ring atoms being carbon and
wherein at least one heteroatom is present in an aromatic ring. For
example, heteroaryl includes a 5- to 7-membered heterocycloalkyl,
aromatic ring fused to a 5- to 7-membered cycloalkyl ring. For such
fused, bicyclic heteroaryl ring systems wherein only one of the
rings contains one or more heteroatoms, the point of attachment may
be at the heteroaromatic ring or the cycloalkyl ring. In certain
embodiments, when the total number of N, S, and O atoms in the
heteroaryl group exceeds one, the heteroatoms are not adjacent to
one another. In certain embodiments, the total number of N, S, and
O atoms in the heteroaryl group is not more than two. In certain
embodiments, the total number of N, S, and O atoms in the aromatic
heterocycle is not more than one. Heteroaryl does not encompass or
overlap with aryl as defined herein.
[0047] Examples of heteroaryl groups include, but are not limited
to, groups derived from acridine, arsindole, carbazole,
.beta.-carboline, chromane, chromene, cinnoline, furan, imidazole,
indazole, indole, indoline, indolizine, isobenzofuran, isochromene,
isoindole, isoindoline, isoquinoline, isothiazole, isoxazole,
naphthyridine, oxadiazole, oxazole, perimidine, phenanthridine,
phenanthroline, phenazine, phthalazine, pteridine, purine, pyran,
pyrazine, pyrazole, pyridazine, pyridine, pyrimidine, pyrrole,
pyrrolizine, quinazoline, quinoline, quinolizine, quinoxaline,
tetrazole, thiadiazole, thiazole, thiophene, triazole, xanthene,
and the like. In certain embodiments, a heteroaryl group is from 5-
to 20-membered heteroaryl, and in certain embodiments from 5- to
12-membered heteroaryl or from 5- to 10-membered heteroaryl. In
certain embodiments, a heteroaryl group is a 5-, 6-, 7-, 8-, 9-,
10-, 11-, 12-, 13-, 14-, 15-, 16-, 17-, 18-, 19-, or 20-membered
heteroaryl. In certain embodiments heteroaryl groups are those
derived from thiophene, pyrrole, benzothiophene, benzofuran,
indole, pyridine, quinoline, imidazole, oxazole, and pyrazine.
[0048] "Heteroarylalkyl" by itself or as part of another
substituent refers to an acyclic alkyl radical in which one of the
hydrogen atoms bonded to a carbon atom, typically a terminal or
sp.sup.3 carbon atom, is replaced with a heteroaryl group. Where
specific alkyl moieties are intended, the nomenclature
heteroarylalkanyl, heteroarylalkenyl, or heteroarylalkynyl is used.
In certain embodiments, a heteroarylalkyl group is a 6- to
30-membered heteroarylalkyl, e.g., the alkanyl, alkenyl, or alkynyl
moiety of the heteroarylalkyl is 1- to 10-membered and the
heteroaryl moiety is a 5- to 20-membered heteroaryl, and in certain
embodiments, 6- to 20-membered heteroarylalkyl, e.g., the alkanyl,
alkenyl, or alkynyl moiety of the heteroarylalkyl is 1- to
8-membered and the heteroaryl moiety is a 5- to 12-membered
heteroaryl.
[0049] "Heterocycloalkyl" by itself or as part of another
substituent refers to a partially saturated or unsaturated cyclic
alkyl radical in which one or more carbon atoms (and any associated
hydrogen atoms) are independently replaced with the same or
different heteroatom. Examples of heteroatoms to replace the carbon
atom(s) include, but are not limited to, N, P, O, S, Si, etc. Where
a specific level of saturation is intended, the nomenclature
"heterocycloalkanyl" or "heterocycloalkenyl" is used. Examples of
heterocycloalkyl groups include, but are not limited to, groups
derived from epoxides, azirines, thiiranes, imidazolidine,
morpholine, piperazine, piperidine, pyrazolidine, pyrrolidine,
quinuclidine, and the like.
[0050] "Heterocycloalkylalkyl" by itself or as part of another
substituent refers to an acyclic alkyl radical in which one of the
hydrogen atoms bonded to a carbon atom, typically a terminal or
sp.sup.3 carbon atom, is replaced with a heterocycloalkyl group.
Where specific alkyl moieties are intended, the nomenclature
heterocycloalkylalkanyl, heterocycloalkylalkenyl, or
heterocycloalkylalkynyl is used. In certain embodiments, a
heterocycloalkylalkyl group is a 6- to 30-membered
heterocycloalkylalkyl, e.g., the alkanyl, alkenyl, or alkynyl
moiety of the heterocycloalkylalkyl is 1- to 10-membered and the
heterocycloalkyl moiety is a 5- to 20-membered heterocycloalkyl,
and in certain embodiments, 6- to 20-membered
heterocycloalkylalkyl, e.g., the alkanyl, alkenyl, or alkynyl
moiety of the heterocycloalkylalkyl is 1- to 8-membered and the
heterocycloalkyl moiety is a 5- to 12-membered
heterocycloalkyl.
[0051] "Mixture" refers to a collection of molecules or chemical
substances. Each component in a mixture can be independently
varied. A mixture may contain, or consist essentially of, two or
more substances intermingled with or without a constant percentage
composition, wherein each component may or may not retain its
essential original properties, and where molecular phase mixing may
or may not occur. In mixtures, the components making up the mixture
may or may not remain distinguishable from each other by virtue of
their chemical structure.
[0052] "Parent aromatic ring system" refers to an unsaturated
cyclic or polycyclic ring system having a conjugated .pi. (pi)
electron system. Included within the definition of "parent aromatic
ring system" are fused ring systems in which one or more of the
rings are aromatic and one or more of the rings are saturated or
unsaturated, such as, for example, fluorene, indane, indene,
phenalene, etc. Examples of parent aromatic ring systems include,
but are not limited to, aceanthrylene, acenaphthylene,
acephenanthrylene, anthracene, azulene, benzene, chrysene,
coronene, fluoranthene, fluorene, hexacene, hexaphene, hexylene,
as-indacene, s-indacene, indane, indene, naphthalene, octacene,
octaphene, octalene, ovalene, penta-2,4-diene, pentacene,
pentalene, pentaphene, perylene, phenalene, phenanthrene, picene,
pleiadene, pyrene, pyranthrene, rubicene, triphenylene,
trinaphthalene, and the like.
[0053] "Parent heteroaromatic ring system" refers to a parent
aromatic ring system in which one or more carbon atoms (and any
associated hydrogen atoms) are independently replaced with the same
or different heteroatom. Examples of heteroatoms to replace the
carbon atoms include, but are not limited to, N, P, O, S, Si, etc.
Specifically included within the definition of "parent
heteroaromatic ring systems" are fused ring systems in which one or
more of the rings are aromatic and one or more of the rings are
saturated or unsaturated, such as, for example, arsindole,
benzodioxan, benzofuran, chromane, chromene, indole, indoline,
xanthene, etc. Examples of parent heteroaromatic ring systems
include, but are not limited to, arsindole, carbazole,
.beta.-carboline, chromane, chromene, cinnoline, furan, imidazole,
indazole, indole, indoline, indolizine, isobenzofuran, isochromene,
isoindole, isoindoline, isoquinoline, isothiazole, isoxazole,
naphthyridine, oxadiazole, oxazole, perimidine, phenanthridine,
phenanthroline, phenazine, phthalazine, pteridine, purine, pyran,
pyrazine, pyrazole, pyridazine, pyridine, pyrimidine, pyrrole,
pyrrolizine, quinazoline, quinoline, quinolizine, quinoxaline,
tetrazole, thiadiazole, thiazole, thiophene, triazole, xanthene,
and the like.
[0054] "Substituted" refers to a group in which one or more
hydrogen atoms are independently replaced with the same or
different substituent(s). Examples of substituents include, but are
not limited to, --R.sup.64, --R.sup.60, --O.sup.-, --OH, .dbd.O,
--OR.sup.60, --SR.sup.60, --S.sup.-, .dbd.S, --NR.sup.60R.sup.61,
.dbd.NR.sup.60, --CN, --CF.sub.3, --OCN, --SCN, --NO, --NO.sub.2,
.dbd.N.sub.2, --N.sub.3, --S(O).sub.2O.sup.-, --S(O).sub.2OH,
--S(O).sub.2R.sup.60, --OS(O.sub.2)O.sup.-, --OS(O).sub.2R.sup.60,
--P(O)(O.sup.-).sub.2, --P(O)(OR.sup.60)(O.sup.-),
--OP(O)(OR.sup.60)(OR.sup.61), --C(O)R.sup.60, --C(S)R.sup.60,
--C(O)OR.sup.60, --C(O)NR.sup.60R.sup.61, --C(O)O.sup.-,
--C(S)OR.sup.60, --NR.sup.62C(O)NR.sup.60R.sup.61,
--NR.sup.62C(S)NR.sup.60R.sup.61,
--NR.sup.62C(NR.sup.63)NR.sup.60R.sup.61,
--C(NR.sup.62)NR.sup.60R.sup.61, --S(O).sub.2, NR.sup.60R.sup.61,
--NR.sup.63S(O).sub.2R.sup.60, --NR.sup.63C(O)R.sup.60, and
--S(O)R.sup.60;
[0055] wherein each --R.sup.64 is independently a halogen; each
R.sup.60 and R.sup.61 are independently alkyl, substituted alkyl,
alkoxy, substituted alkoxy, cycloalkyl, substituted cycloalkyl,
heterocycloalkyl, substituted heterocycloalkyl, aryl, substituted
aryl, heteroaryl, substituted heteroaryl, arylalkyl, substituted
arylalkyl, heteroarylalkyl, or substituted heteroarylalkyl, or
R.sup.60 and R.sup.61 together with the nitrogen atom to which they
are bonded form a heterocycloalkyl, substituted heterocycloalkyl,
heteroaryl, or substituted heteroaryl ring, and R.sup.62 and
R.sup.63 are independently alkyl, substituted alkyl, aryl,
substituted aryl, arylalkyl, substituted arylalkyl, cycloalkyl,
substituted cycloalkyl, heterocycloalkyl, substituted
heterocycloalkyl, heteroaryl, substituted heteroaryl,
heteroarylalkyl, or substituted heteroarylalkyl, or R.sup.62 and
R.sup.63 together with the atom to which they are bonded form one
or more heterocycloalkyl, substituted heterocycloalkyl, heteroaryl,
or substituted heteroaryl rings;
[0056] wherein the "substituted" substituents, as defined above for
R.sup.60, R.sup.61, R.sup.62, and R.sup.63, are substituted with
one or more, such as one, two, or three, groups independently
selected from alkyl, -alkyl-OH, --O-haloalkyl, -alkyl-NH.sub.2,
alkoxy, cycloalkyl, cycloalkylalkyl, heterocycloalkyl,
heterocycloalkylalkyl, aryl, heteroaryl, arylalkyl,
heteroarylalkyl, --O.sup.-, --OH, .dbd.O, --O-alkyl, --O-aryl,
--O-heteroarylalkyl, --O-cycloalkyl, --O-heterocycloalkyl, --SH,
--S.sup.-, .dbd.S, --S-alkyl, --S-aryl, --S-heteroarylalkyl,
--S-cycloalkyl, --S-heterocycloalkyl, --NH.sub.2, .dbd.NH, --CN,
--CF.sub.3, --OCN, --SCN, --NO, --NO.sub.2, .dbd.N.sub.2,
--N.sub.3, --S(O).sub.2O.sup.-, --S(O).sub.2, --S(O).sub.2OH,
--OS(O.sub.2)O.sup.-, --SO.sub.2(alkyl), --SO.sub.2(phenyl),
--SO.sub.2(haloalkyl), --SO.sub.2NH.sub.2, --SO.sub.2NH(alkyl),
--SO.sub.2NH(phenyl), --P(O)(O.sup.-).sub.2,
--P(O)(O-alkyl)(O.sup.-), --OP(O)(O-alkyl)(O-alkyl), --CO.sub.2H,
--C(O)O(alkyl), --CON(alkyl)(alkyl), --CONH(alkyl), --CONH.sub.2,
--C(O)(alkyl), --C(O)(phenyl), --C(O)(haloalkyl), --OC(O)(alkyl),
--N(alkyl)(alkyl), --NH(alkyl), --N(alkyl)(alkylphenyl),
--NH(alkylphenyl), --NHC(O)(alkyl), --NHC(O)(phenyl),
--N(alkyl)C(O)(alkyl), and --N(alkyl)C(O)(phenyl).
[0057] As used in this specification and the appended claims, the
articles "a," "an," and "the" include plural referents unless
expressly and unequivocally limited to one referent.
[0058] The term "fatty acid" refers to any natural or synthetic
carboxylic acid comprising an alkyl chain that may be saturated,
monounsaturated, or polyunsaturated, and may have straight or
branched chains. The fatty acid may also be substituted. "Fatty
acid," as used herein, includes short chain alkyl carboxylic acid
including, for example, acetic acid, propionic acid, etc.
[0059] All numerical ranges herein include all numerical values and
ranges of all numerical values within the recited range of
numerical values.
[0060] The present disclosure relates to estolide compounds,
compositions and methods of making the same. In certain
embodiments, the present disclosure also relates to estolide
compounds, compositions comprising estolide compounds, the
synthesis of such compounds, and the formulation of such
compositions. In certain embodiments, the present disclosure
relates to cooking oils, frying oils, and food additives comprising
one or more estolide compounds. In certain embodiments are
described methods of preparing food products, comprising cooking at
least one article of food in a composition comprising at least one
estolide compound.
[0061] In certain embodiments, the estolides comprise at least one
compound of Formula I:
##STR00004##
[0062] wherein
[0063] x is, independently for each occurrence, an integer selected
from 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, and 10;
[0064] y is, independently for each occurrence, an integer selected
from 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, and 10;
[0065] n is an integer selected from 0, 1, 2, 3, 4, 5, 6, 7, 8, 9,
10, 11, and 12;
[0066] R.sub.1 is an optionally substituted alkyl that is saturated
or unsaturated, and branched or unbranched; and
[0067] R.sub.2 is selected from hydrogen and an optionally
substituted alkyl that is saturated or unsaturated, and branched or
unbranched;
[0068] wherein each fatty acid chain residue of said at least one
compound is independently optionally substituted.
[0069] In certain embodiments, the estolides comprise at least one
compound of Formula II:
##STR00005##
[0070] wherein
[0071] m is an integer equal to or greater than 1;
[0072] n is an integer equal to or greater than 0;
[0073] R.sub.1, independently for each occurrence, is an optionally
substituted alkyl that is saturated or unsaturated, and branched or
unbranched;
[0074] R.sub.2 is selected from hydrogen and optionally substituted
alkyl that is saturated or unsaturated, and branched or unbranched;
and
[0075] R.sub.3 and R.sub.4, independently for each occurrence, are
selected from optionally substituted alkyl that is saturated or
unsaturated, and branched or unbranched.
[0076] In certain embodiments, the estolides comprise at least one
estolide compound of Formula III:
##STR00006##
[0077] wherein
[0078] x is, independently for each occurrence, an integer selected
from 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17,
18, 19, and 20;
[0079] y is, independently for each occurrence, an integer selected
from 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17,
18, 19, and 20;
[0080] n is an integer equal to or greater than 0;
[0081] R.sub.1 is an optionally substituted alkyl that is saturated
or unsaturated, and branched or unbranched; and
[0082] R.sub.2 is selected from hydrogen and an optionally
substituted alkyl that is saturated or unsaturated, and branched or
unbranched;
[0083] wherein each fatty acid chain residue of said at least one
compound is independently optionally substituted.
[0084] In certain embodiments, the composition comprises at least
one estolide of Formula I, II, or III where R.sub.1 is
hydrogen.
[0085] The terms "chain" or "fatty acid chain" or "fatty acid chain
residue," as used with respect to the estolide compounds of Formula
I, II, and III, refer to one or more of the fatty acid residues
incorporated in estolide compounds, e.g., R.sub.3 or R.sub.4 of
Formula II, or the structures represented by
CH.sub.3(CH.sub.2).sub.yCH(CH.sub.2).sub.xC(O)O-- in Formula I and
III.
[0086] The R.sub.1 in Formula I, II, and III at the top of each
Formula shown is an example of what may be referred to as a "cap"
or "capping material," as it "caps" the top of the estolide.
Similarly, the capping group may be an organic acid residue of
general formula --OC(O)-alkyl, i.e., a carboxylic acid with a
substituted or unsubstituted, saturated or unsaturated, and/or
branched or unbranched alkyl as defined herein, or a formic acid
residue. In certain embodiments, the "cap" or "capping group" is a
fatty acid. In certain embodiments, the capping group, regardless
of size, is substituted or unsubstituted, saturated or unsaturated,
and/or branched or unbranched. The cap or capping material may also
be referred to as the primary or alpha (.alpha.) chain.
[0087] Depending on the manner in which the estolide is
synthesized, the cap or capping group alkyl may be the only alkyl
from an organic acid residue in the resulting estolide that is
unsaturated. In certain embodiments, it may be desirable to use a
saturated organic or fatty-acid cap to increase the overall
saturation of the estolide and/or to increase the resulting
estolide's stability. For example, in certain embodiments, it may
be desirable to provide a method of providing a saturated capped
estolide by hydrogenating an unsaturated cap using any suitable
methods available to those of ordinary skill in the art.
Hydrogenation may be used with various sources of the fatty-acid
feedstock, which may include mono- and/or polyunsaturated fatty
acids. Without being bound to any particular theory, in certain
embodiments, hydrogenating the estolide may help to improve the
overall stability of the molecule. However, a fully-hydrogenated
estolide, such as an estolide with a larger fatty acid cap, may
exhibit increased pour point temperatures. In certain embodiments,
it may be desirable to offset any loss in desirable pour-point
characteristics by using shorter, saturated capping materials.
[0088] The R.sub.4C(O)O-- of Formula II or structure
CH.sub.3(CH.sub.2).sub.yCH(CH.sub.2).sub.xC(O)O-- of Formula I and
III serve as the "base" or "base chain residue" of the estolide.
Depending on the manner in which the estolide is synthesized, the
base organic acid or fatty acid residue may be the only residue
that remains in its free-acid form after the initial synthesis of
the estolide. However, in certain embodiments, in an effort to
alter or improve the properties of the estolide, the free acid may
be reacted with any number of substituents. For example, it may be
desirable to react the free acid estolide with alcohols, glycols,
amines, or other suitable reactants to provide the corresponding
ester, amide, or other reaction products. The base or base chain
residue may also be referred to as tertiary or gamma (.gamma.)
chains.
[0089] The R.sub.3C(O)O-- of Formula II or structure
CH.sub.3(CH.sub.2).sub.yCH(CH.sub.2).sub.xC(O)O-- of Formula I and
III are linking residues that link the capping material and the
base fatty-acid residue together. There may be any number of
linking residues in the estolide, including when n=0 and the
estolide is in its dimer form. Depending on the manner in which the
estolide is prepared, a linking residue may be a fatty acid and may
initially be in an unsaturated form during synthesis. In some
embodiments, the estolide will be formed when a catalyst is used to
produce a carbocation at the fatty acid's site of unsaturation,
which is followed by nucleophilic attack on the carbocation by the
carboxylic group of another fatty acid. In some embodiments, it may
be desirable to have a linking fatty acid that is monounsaturated
so that when the fatty acids link together, all of the sites of
unsaturation are eliminated. The linking residue(s) may also be
referred to as secondary or beta (.beta.) chains.
[0090] In certain embodiments, the cap is an acetyl group, the
linking residue(s) is one or more fatty acid residues, and the base
chain residue is a fatty acid residue. In certain embodiments, the
linking residues present in an estolide differ from one another. In
certain embodiments, one or more of the linking residues differs
from the base chain residue.
[0091] As noted above, in certain embodiments, suitable unsaturated
fatty acids for preparing the estolides may include any mono- or
polyunsaturated fatty acid. For example, monounsaturated fatty
acids, along with a suitable catalyst, will form a single
carbocation that allows for the addition of a second fatty acid,
whereby a single link between two fatty acids is formed. Suitable
monounsaturated fatty acids may include, but are not limited to,
palmitoleic acid (16:1), vaccenic acid (18:1), oleic acid (18:1),
eicosenoic acid (20:1), erucic acid (22:1), and nervonic acid
(24:1). In addition, in certain embodiments, polyunsaturated fatty
acids may be used to create estolides. Suitable polyunsaturated
fatty acids may include, but are not limited to, hexadecatrienoic
acid (16:3), alpha-linolenic acid (18:3), stearidonic acid (18:4),
eicosatrienoic acid (20:3), eicosatetraenoic acid (20:4),
eicosapentaenoic acid (20:5), heneicosapentaenoic acid (21:5),
docosapentaenoic acid (22:5), docosahexaenoic acid (22:6),
tetracosapentaenoic acid (24:5), tetracosahexaenoic acid (24:6),
linoleic acid (18:2), gamma-linoleic acid (18:3), eicosadienoic
acid (20:2), dihomo-gamma-linolenic acid (20:3), arachidonic acid
(20:4), docosadienoic acid (20:2), adrenic acid (22:4),
docosapentaenoic acid (22:5), tetracosatetraenoic acid (22:4),
tetracosapentaenoic acid (24:5), pinolenic acid (18:3), podocarpic
acid (20:3), rumenic acid (18:2), alpha-calendic acid (18:3),
beta-calendic acid (18:3), jacaric acid (18:3), alpha-eleostearic
acid (18:3), beta-eleostearic (18:3), catalpic acid (18:3), punicic
acid (18:3), rumelenic acid (18:3), alpha-parinaric acid (18:4),
beta-parinaric acid (18:4), and bosseopentaenoic acid (20:5). In
certain embodiments, hydroxy fatty acids may be polymerized or
homopolymerized by reacting the carboxylic acid functionality of
one fatty acid with the hydroxy functionality of a second fatty
acid. Exemplary hydroxyl fatty acids include, but are not limited
to, ricinoleic acid, 6-hydroxystearic acid, 9,10-dihydroxystearic
acid, 12-hydroxystearic acid, and 14-hydroxystearic acid.
[0092] The process for preparing the estolide compounds described
herein may include the use of any natural or synthetic fatty acid
source. However, it may be desirable to source the fatty acids from
a renewable biological feedstock. For example, suitable starting
materials of biological origin include, but are not limited to,
plant fats, plant oils, plant waxes, animal fats, animal oils,
animal waxes, fish fats, fish oils, fish waxes, algal oils and
mixtures of two or more thereof. Other potential fatty acid sources
include, but are not limited to, waste and recycled food-grade fats
and oils, fats, oils, and waxes obtained by genetic engineering,
fossil fuel-based materials and other sources of the materials
desired.
[0093] In certain embodiments, the compounds described herein may
be prepared from non-naturally occurring fatty acids derived from
naturally occurring feedstocks. In certain embodiments, the
compounds are prepared from synthetic fatty acid products derived
from naturally occurring feedstocks such as vegetable oils. For
example, the synthetic fatty acid product may be prepared by
cleaving fragments from larger fatty acid residues occurring in
natural oils, such as triglycerides, using any of the suitable
metathesis processes described further below. In certain
embodiments, the resulting truncated fatty acid residue(s) may then
be liberated from the glycerine backbone using any suitable
hydrolytic and/or transesterification processes known to those of
skill in the art. An exemplary fatty acid product includes
9-dodecenoic acid, which may be prepared via the cross metathesis
of an oleic acid residue with 1-butene. In certain embodiments, the
naturally-occurring fatty acid may be liberated from the glycerine
backbone prior to being exposed to metathesis. Such metathesis
reactions may be non-specific and produce mixtures of products,
wherein reactions producing, for example, internally-unsaturated
fatty acids such as 9-dodecenoic acid also produce varying amounts
of the terminally-unsaturated fatty acid, 9-decenoic acid. In
certain embodiments, it may be desirable to optimize the production
of fatty acids having at least one terminal site of unsaturation by
reacting an unsaturated fatty acid reactant (e.g., oleic acid) with
ethylene under metathesis conditions, whereby the
terminally-unsaturated fatty acid product (e.g., 9-decenoic acid)
is produced exclusively.
[0094] In some embodiments, the compound comprises fatty-acid
chains of varying lengths. In some embodiments, x is, independently
for each occurrence, an integer selected from 0 to 20, 0 to 18, 0
to 16, 0 to 14, 1 to 12, 1 to 10, 2 to 8, 6 to 8, or 4 to 6. In
some embodiments, x is, independently for each occurrence, an
integer selected from 7 and 8. In some embodiments, x is,
independently for each occurrence, an integer selected from 0, 1,
2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, and
20. In certain embodiments, for at least one fatty acid chain
residue, x is an integer selected from 7 and 8.
[0095] In some embodiments, y is, independently for each
occurrence, an integer selected from 0 to 20, 0 to 18, 0 to 16, 0
to 14, 1 to 12, 1 to 10, 2 to 8, 6 to 8, or 4 to 6. In some
embodiments, y is, independently for each occurrence, an integer
selected from 7 and 8. In some embodiments, y is, independently for
each occurrence, an integer selected from 0, 1, 2, 3, 4, 5, 6, 7,
8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, and 20. In certain
embodiments, for at least one fatty acid chain residue, y is an
integer selected from 7 and 8. In some embodiments, for at least
one fatty acid chain residue, y is an integer selected from 0 to 6,
or 1 and 2. In certain embodiments, y is, independently for each
occurrence, an integer selected from 1 to 6, or 1 and 2.
[0096] In some embodiments, x+y is, independently for each chain,
an integer selected from 0 to 40, 0 to 20, 10 to 20, or 12 to 18.
In some embodiments, x+y is, independently for each chain, an
integer selected from 13 to 15. In some embodiments, x+y is 15. In
some embodiments, x+y is, independently for each chain, an integer
selected from 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19,
20, 21, 22, 23, and 24. In certain embodiments, x+y, independently
for each chain, is an integer selected from 5 to 15. In certain
embodiments, for at least one fatty acid chain residue, x+y is 7.
In certain embodiments, x+y is 7 for each fatty acid chain residue.
In certain embodiments, for at least one fatty acid chain residue,
x+y is an integer selected from 9 to 13. In certain embodiments,
for at least one fatty acid chain residue, x+y is 9. In certain
embodiments, x+y is, independently for each chain, an integer
selected from 9 to 13. In certain embodiments, x+y is 9 for each
fatty acid chain residue.
[0097] In some embodiments, the estolide compound of Formula I, II,
or III may comprise any number of fatty acid residues to form an
"n-mer" estolide. For example, the estolide may be in its dimer
(n=0), trimer (n=1), tetramer (n=2), pentamer (n=3), hexamer (n=4),
heptamer (n=5), octamer (n=6), nonamer (n=7), or decamer (n=8)
form. In some embodiments, n is an integer selected from 0 to 20, 0
to 18, 0 to 16, 0 to 14, 0 to 12, 0 to 10, 0 to 8, or 0 to 6. In
some embodiments, n is an integer selected from 0 to 4. In some
embodiments, n is 1, wherein said at least one compound of Formula
I, II, or III comprises the trimer. In some embodiments, n is
greater than 1. In some embodiments, n is an integer selected from
0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18,
19, and 20.
[0098] In some embodiments, R.sub.1 of Formula I, II, or III is an
optionally substituted alkyl that is saturated or unsaturated, and
branched or unbranched. In some embodiments, the alkyl group is a
C.sub.1 to C.sub.40 alkyl, C.sub.1 to C.sub.22 alkyl or C.sub.1 to
C.sub.18 alkyl. In some embodiments, the alkyl group is selected
from C.sub.7 to C.sub.17 alkyl. In some embodiments, R.sub.1 is
selected from C.sub.7 alkyl, C.sub.9 alkyl, C.sub.11 alkyl,
C.sub.13 alkyl, C.sub.15 alkyl, and C.sub.17 alkyl. In some
embodiments, R.sub.1 is selected from C.sub.13 to C.sub.17 alkyl,
such as from C.sub.13 alkyl, C.sub.15 alkyl, and C.sub.17 alkyl. In
some embodiments, R.sub.1 is a C.sub.1, C.sub.2, C.sub.3, C.sub.4,
C.sub.5, C.sub.6, C.sub.7, C.sub.8, C.sub.9, C.sub.10, C.sub.11,
C.sub.12, C.sub.13, C.sub.14, C.sub.15, C.sub.16, C.sub.17,
C.sub.18, C.sub.19, C.sub.20, C.sub.21, or C.sub.22 alkyl.
[0099] In some embodiments, R.sub.2 of Formula I, II, or III is an
optionally substituted alkyl that is saturated or unsaturated, and
branched or unbranched. In some embodiments, the alkyl group is a
C.sub.1 to C.sub.40 alkyl, C.sub.1 to C.sub.22 alkyl or C.sub.1 to
C.sub.18 alkyl. In some embodiments, the alkyl group is selected
from C.sub.7 to C.sub.17 alkyl. In some embodiments, R.sub.2 is
selected from C.sub.7 alkyl, C.sub.9 alkyl, C.sub.11 alkyl,
C.sub.13 alkyl, C.sub.15 alkyl, and C.sub.17 alkyl. In some
embodiments, R.sub.2 is selected from C.sub.13 to C.sub.17 alkyl,
such as from C.sub.13 alkyl, C.sub.15 alkyl, and C.sub.17 alkyl. In
some embodiments, R.sub.2 is a C.sub.1, C.sub.2, C.sub.3, C.sub.4,
C.sub.5, C.sub.6, C.sub.7, C.sub.8, C.sub.9, C.sub.10, C.sub.11,
C.sub.12, C.sub.13, C.sub.14, C.sub.15, C.sub.16, C.sub.17,
C.sub.18, C.sub.19, C.sub.20, C.sub.21, or C.sub.22 alkyl.
[0100] In some embodiments, R.sub.3 is an optionally substituted
alkyl that is saturated or unsaturated, and branched or unbranched.
In some embodiments, the alkyl group is a C.sub.1 to C.sub.40
alkyl, C.sub.1 to C.sub.22 alkyl or C.sub.1 to C.sub.18 alkyl. In
some embodiments, the alkyl group is selected from C.sub.7 to
C.sub.17 alkyl. In some embodiments, R.sub.3 is selected from
C.sub.7 alkyl, C.sub.9 alkyl, C.sub.11 alkyl, C.sub.13 alkyl,
C.sub.15 alkyl, and C.sub.17 alkyl. In some embodiments, R.sub.3 is
selected from C.sub.13 to C.sub.17 alkyl, such as from C.sub.13
alkyl, C.sub.15 alkyl, and C.sub.17 alkyl. In some embodiments,
R.sub.3 is a C.sub.1, C.sub.2, C.sub.3, C.sub.4, C.sub.5, C.sub.6,
C.sub.7, C.sub.8, C.sub.9, C.sub.10, C.sub.11, C.sub.12, C.sub.13,
C.sub.14, C.sub.15, C.sub.16, C.sub.17, C.sub.18, C.sub.19,
C.sub.20, C.sub.21, or C.sub.22 alkyl.
[0101] In some embodiments, R.sub.4 is an optionally substituted
alkyl that is saturated or unsaturated, and branched or unbranched.
In some embodiments, the alkyl group is a C.sub.1 to C.sub.40
alkyl, C.sub.1 to C.sub.22 alkyl or C.sub.1 to C.sub.18 alkyl. In
some embodiments, the alkyl group is selected from C.sub.7 to
C.sub.17 alkyl. In some embodiments, R.sub.4 is selected from
C.sub.7 alkyl, C.sub.9 alkyl, C.sub.11 alkyl, C.sub.13 alkyl,
C.sub.15 alkyl, and C.sub.17 alkyl. In some embodiments, R.sub.4 is
selected from C.sub.13 to C.sub.17 alkyl, such as from C.sub.13
alkyl, C.sub.15 alkyl, and C.sub.17 alkyl. In some embodiments,
R.sub.4 is a C.sub.1, C.sub.2, C.sub.3, C.sub.4, C.sub.5, C.sub.6,
C.sub.7, C.sub.8, C.sub.9, C.sub.10, C.sub.11, C.sub.12, C.sub.13,
C.sub.14, C.sub.15, C.sub.16, C.sub.17, C.sub.18, C.sub.19,
C.sub.20, C.sub.21, or C.sub.22 alkyl.
[0102] As noted above, in certain embodiments, it may be possible
to manipulate one or more of the estolides' properties by altering
the length of R.sub.1 and/or its degree of saturation. However, in
certain embodiments, the level of substitution on R.sub.1 may also
be altered to change or even improve the estolides' properties.
Without being bound to any particular theory, in certain
embodiments, it is believed that the presence of polar substituents
on R.sub.1, such as one or more hydroxy groups, may increase the
viscosity of the estolide, while increasing pour point.
Accordingly, in some embodiments, R.sub.1 will be unsubstituted or
optionally substituted with a group that is not hydroxyl.
[0103] In some embodiments, the estolide is in its free-acid form,
wherein R.sub.2 of Formula I, II, or III is hydrogen. In some
embodiments, R.sub.2 is selected from optionally substituted alkyl
that is saturated or unsaturated, and branched or unbranched. In
certain embodiments, the R.sub.2 residue may comprise any desired
alkyl group, such as those derived from esterification of the
estolide with the alcohols identified in the examples herein. In
some embodiments, the alkyl group is selected from C.sub.1 to
C.sub.40, C.sub.1 to C.sub.22, C.sub.3 to C.sub.20, C.sub.1 to
C.sub.18, or C.sub.6 to C.sub.12 alkyl. In some embodiments,
R.sub.2 may be selected from C.sub.3 alkyl, C.sub.4 alkyl, C.sub.8
alkyl, C.sub.12 alkyl, C.sub.16 alkyl, C.sub.18 alkyl, and C.sub.20
alkyl. For example, in certain embodiments, R.sub.2 may be
branched, such as isopropyl, isobutyl, or 2-ethylhexyl. In some
embodiments, R.sub.2 may be a larger alkyl group, branched or
unbranched, comprising C.sub.12 alkyl, C.sub.16 alkyl, C.sub.18
alkyl, or C.sub.20 alkyl. Such groups at the R.sub.2 position may
be derived from esterification of the free-acid estolide using the
Jarcol.TM. line of alcohols marketed by Jarchem Industries, Inc. of
Newark, N.J., including Jarcol.TM. I-18CG, I-20, I-12, I-16, I-18T,
and 85BJ. In some cases, R.sub.2 may be sourced from certain
alcohols to provide branched alkyls such as isostearyl and
isopalmityl. It should be understood that such isopalmityl and
isostearyl alkyl groups may cover any branched variation of
C.sub.16 and C.sub.18, respectively. For example, the estolides
described herein may comprise highly-branched isopalmityl or
isostearyl groups at the R.sub.2 position, derived from the
Fineoxocol.RTM. line of isopalmityl and isostearyl alcohols
marketed by Nissan Chemical America Corporation of Houston, Tex.,
including Fineoxocol.RTM. 180, 180N, and 1600. Without being bound
to any particular theory, in certain embodiments, large,
highly-branched alkyl groups (e.g., isopalmityl and isostearyl) at
the R.sub.2 position of the estolides can provide at least one way
to increase an estolide-containing composition's viscosity, while
substantially retaining or even reducing its pour point. In certain
embodiments, branched alcohols such as 2-ethylhexanol may provide
increased stability to the ester bond of the base residue by making
it less susceptible to hydrolysis.
[0104] In some embodiments, the compounds described herein may
comprise a mixture of two or more estolide compounds of Formula I,
II, and III. It is possible to characterize the chemical makeup of
an estolide, a mixture of estolides, or a composition comprising
estolides, by using the compound's, mixture's, or composition's
measured estolide number (EN) of compound or composition. The EN
represents the average number of fatty acids added to the base
fatty acid. The EN also represents the average number of estolide
linkages per molecule:
EN=n+1
wherein n is the number of secondary (.beta.) fatty acids.
Accordingly, a single estolide compound will have an EN that is a
whole number, for example for dimers, trimers, and tetramers:
dimer EN=1
trimer EN=2
tetramer EN=3
[0105] However, a composition comprising two or more estolide
compounds may have an EN that is a whole number or a fraction of a
whole number. For example, a composition having a 1:1 molar ratio
of dimer and trimer would have an EN of 1.5, while a composition
having a 1:1 molar ratio of tetramer and trimer would have an EN of
2.5.
[0106] In some embodiments, the compositions may comprise a mixture
of two or more estolides having an EN that is an integer or
fraction of an integer that is greater than 4.5, or even 5.0. In
some embodiments, the EN may be an integer or fraction of an
integer selected from about 1.0 to about 5.0. In some embodiments,
the EN is an integer or fraction of an integer selected from 1.2 to
about 4.5. In some embodiments, the EN is selected from a value
greater than 1.0, 1.2, 1.4, 1.6, 1.8, 2.0, 2.2, 2.4, 2.6, 2.8, 3.0,
3.2, 3.4, 3.6, 3.8, 4.0, 4.2, 4.4, 4.6, 4.8, 5.0, 5.2, 5.4, 5.6 and
5.8. In some embodiments, the EN is selected from a value less than
1.2, 1.4, 1.6, 1.8, 2.0, 2.2, 2.4, 2.6, 2.8, 3.0, 3.2, 3.4, 3.6,
3.8, 4.0, 4.2, 4.4, 4.6, 4.8, and 5.0, 5.2, 5.4, 5.6, 5.8, and 6.0.
In some embodiments, the EN is selected from 1, 1.2, 1.4, 1.6, 1.8,
2.0, 2.2, 2.4, 2.6, 2.8, 3.0, 3.2, 3.4, 3.6, 3.8, 4.0, 4.2, 4.4,
4.6, 4.8, 5.0, 5.2, 5.4, 5.6, 5.8, and 6.0.
[0107] As noted above, it should be understood that the chains of
the estolide compounds may be independently optionally substituted,
wherein one or more hydrogens are removed and replaced with one or
more of the substituents identified herein. Similarly, two or more
of the hydrogen residues may be removed to provide one or more
sites of unsaturation, such as a cis or trans double bond. Further,
the chains may optionally comprise branched hydrocarbon residues.
For example, in some embodiments the estolides described herein may
comprise at least one compound of Formula II:
##STR00007##
[0108] wherein
[0109] m is an integer equal to or greater than 1;
[0110] n is an integer equal to or greater than 0;
[0111] R.sub.1, independently for each occurrence, is an optionally
substituted alkyl that is saturated or unsaturated, and branched or
unbranched;
[0112] R.sub.2 is selected from hydrogen and optionally substituted
alkyl that is saturated or unsaturated, and branched or unbranched;
and
[0113] R.sub.3 and R.sub.4, independently for each occurrence, are
selected from optionally substituted alkyl that is saturated or
unsaturated, and branched or unbranched.
[0114] In certain embodiments, m is 1. In some embodiments, m is an
integer selected from 2, 3, 4, and 5. In some embodiments, n is an
integer selected from 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, and 12. In
some embodiments, one or more R.sub.3 differs from one or more
other R.sub.3 in a compound of Formula II. In some embodiments, one
or more R.sub.3 differs from R.sub.4 in a compound of Formula II.
In some embodiments, if the compounds of Formula II are prepared
from one or more polyunsaturated fatty acids, it is possible that
one or more of R.sub.3 and R.sub.4 will have one or more sites of
unsaturation. In some embodiments, if the compounds of Formula II
are prepared from one or more branched fatty acids, it is possible
that one or more of R.sub.3 and R.sub.4 will be branched.
[0115] In some embodiments, R.sub.3 and R.sub.4 can be
CH.sub.3(CH.sub.2).sub.yCH(CH.sub.2).sub.x--, where x is,
independently for each occurrence, an integer selected from 0, 1,
2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, and
20, and y is, independently for each occurrence, an integer
selected from 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15,
16, 17, 18, 19, and 20. Where both R.sub.3 and R.sub.4 are
CH.sub.3(CH.sub.2).sub.yCH(CH.sub.2).sub.x--, the compounds may be
compounds according to Formula I and III.
[0116] Typically, base stocks and estolide-containing compositions
exhibit certain lubricity, viscosity, and/or pour point
characteristics. For example, in certain embodiments, the base
oils, compounds, and compositions may exhibit viscosities that
range from about 10 cSt to about 250 cSt at 40.degree. C., and/or
about 3 cSt to about 30 cSt at 100.degree. C. In some embodiments,
the base oils, compounds, and compositions may exhibit viscosities
within a range from about 50 cSt to about 150 cSt at 40.degree. C.,
and/or about 10 cSt to about 20 cSt at 100.degree. C.
[0117] In some embodiments, the estolide compounds and compositions
may exhibit viscosities less than about 55 cSt at 40.degree. C. or
less than about 45 cSt at 40.degree. C., and/or less than about 12
cSt at 100.degree. C. or less than about 10 cSt at 100.degree. C.
In some embodiments, the estolide compounds and compositions may
exhibit viscosities within a range from about 25 cSt to about 55
cSt at 40.degree. C., and/or about 5 cSt to about 11 cSt at
100.degree. C. In some embodiments, the estolide compounds and
compositions may exhibit viscosities within a range from about 35
cSt to about 45 cSt at 40.degree. C., and/or about 6 cSt to about
10 cSt at 100.degree. C. In some embodiments, the estolide
compounds and compositions may exhibit viscosities within a range
from about 38 cSt to about 43 cSt at 40.degree. C., and/or about 7
cSt to about 9 cSt at 100.degree. C.
[0118] In some embodiments, estolide compounds and compositions may
exhibit desirable low-temperature pour point properties. In some
embodiments, the estolide compounds and compositions may exhibit a
pour point lower than about -25.degree. C., about -35.degree. C.,
-40.degree. C., or even about -50.degree. C. In some embodiments,
the estolide compounds and compositions have a pour point of about
-25.degree. C. to about -45.degree. C. In some embodiments, the
pour point falls within a range of about -30.degree. C. to about
-40.degree. C., about -34.degree. C. to about -38.degree. C., about
-30.degree. C. to about -45.degree. C., -35.degree. C. to about
-45.degree. C., 34.degree. C. to about -42.degree. C., about
-38.degree. C. to about -42.degree. C., or about 36.degree. C. to
about -40.degree. C.
[0119] In addition, in certain embodiments, the estolides may
exhibit decreased Iodine Values (IV) when compared to estolides
prepared by other methods. IV is a measure of the degree of total
unsaturation of an oil, and is determined by measuring the amount
of iodine per gram of estolide (cg/g). In certain instances, oils
having a higher degree of unsaturation may be more susceptible to
creating corrosiveness and deposits, and may exhibit lower levels
of oxidative stability. Compounds having a higher degree of
unsaturation will have more points of unsaturation for iodine to
react with, resulting in a higher IV. Thus, in certain embodiments,
it may be desirable to reduce the IV of estolides in an effort to
increase the oil's oxidative stability, while also decreasing
harmful deposits and the corrosiveness of the oil.
[0120] In some embodiments, estolide compounds and compositions
described herein have an IV of less than about 40 cg/g or less than
about 35 cg/g. In some embodiments, estolides have an IV of less
than about 30 cg/g, less than about 25 cg/g, less than about 20
cg/g, less than about 15 cg/g, less than about 10 cg/g, or less
than about 5 cg/g. The IV of a composition may be reduced by
decreasing the estolide's degree of unsaturation. This may be
accomplished by, for example, by increasing the amount of saturated
capping materials relative to unsaturated capping materials when
synthesizing the estolides. Alternatively, in certain embodiments,
IV may be reduced by hydrogenating estolides having unsaturated
caps.
[0121] In certain embodiments is described a food product
containing at least one estolide compound. In certain embodiments,
the food product is prepared by a process that includes cooking an
article of food in a composition comprising at least one estolide
compound. In certain embodiments, the cooking comprises heating the
composition to frying temperature, and contacting the article of
food with said composition for a time sufficient to fry said
article of food. In certain embodiments, the frying temperature is
greater than 100.degree. C., such as about 150.degree. C., about
180.degree. C., or about 200.degree. C. In certain embodiments, the
frying temperature is less than about 200.degree. C., such as about
190.degree. C. In certain embodiments, the frying temperature is
selected from a range of about 100.degree. C. to about 200.degree.
C., such as about 150.degree. C. to about 200.degree. C., or about
170.degree. C. to about 190.degree. C.
[0122] In certain embodiments, it is believed that estolides may
generally serve as a replacement for vegetable oil-based
compositions in the food industry. Accordingly, a method of
preparing a food product is also described. In certain embodiments,
the method comprises cooking an article of food in a composition
comprising at least one estolide compound to provide a food
product. In certain embodiments, the method comprises including at
least one estolide compound in an article of food to provide a food
product. In some embodiments, it may be desirable to prepare fry
oil compositions comprising an estolide base stock. In certain
embodiments, a method of extending the fry life of a cooking oil is
described. In certain embodiments, the method comprises contacting
at least one cooking oil with a composition comprising at least one
estolide compound. For example, in certain embodiments, the
estolides described herein may be blended with one or more cooking
oils selected from animal-based oils, vegetable oils,
polyalphaolefins, synthetic esters, polyalkylene glycols, and
mineral oils (Groups I, II, and III). In certain embodiments, the
resulting blended cooking oil will exhibit a fry life that is
longer when compared to the cooking oil that does not include at
least one estolide compound.
[0123] In certain embodiments, the process of producing an estolide
base oil comprises oligomerizing one or more free fatty acids in
the presence of an oligomerization catalyst, wherein the resulting
estolide base oil comprises a free-acid estolide. In certain
embodiments, the oligomerization catalyst comprises one or more
compounds selected from Bronsted acid catalysts and Lewis acid
catalysts, including any known by those of ordinary skill in the
art.
[0124] The present disclosure further relates to methods of making
estolides according to Formula I, II, and III. By way of example,
the reaction of an unsaturated fatty acid with an organic acid and
the esterification of the resulting free acid estolide are
illustrated and discussed in the following Schemes 1 and 2. The
particular structural formulas used to illustrate the reactions
correspond to those for synthesis of compounds according to Formula
I and III; however, the methods apply equally to the synthesis of
compounds according to Formula II, with use of compounds having
structure corresponding to R.sub.3 and R.sub.4 with a reactive site
of unsaturation.
[0125] As illustrated below, compound 100 represents an unsaturated
fatty acid that may serve as the basis for preparing the estolide
compounds described herein.
##STR00008##
[0126] In Scheme 1, wherein x is, independently for each
occurrence, an integer selected from 0 to 20, y is, independently
for each occurrence, an integer selected from 0 to 20, n is an
integer greater than or equal to 1, and R.sub.1 is an optionally
substituted alkyl that is saturated or unsaturated, and branched or
unbranched, unsaturated fatty acid 100 may be combined with
compound 102 and a proton from a proton source to form free acid
estolide 104. In certain embodiments, compound 102 is not included,
and unsaturated fatty acid 100 may be exposed alone to acidic
conditions to form free acid estolide 104, wherein R.sub.1 would
represent an unsaturated alkyl group. In certain embodiments, if
compound 102 is included in the reaction, R.sub.1 may represent one
or more optionally substituted alkyl residues that are saturated or
unsaturated and branched or unbranched. Any suitable proton source
may be implemented to catalyze the formation of free acid estolide
104, including but not limited to homogenous acids and/or strong
acids like hydrochloric acid, sulfuric acid, perchloric acid,
nitric acid, triflic acid, and the like.
##STR00009##
[0127] Similarly, in Scheme 2, wherein x is, independently for each
occurrence, an integer selected from 0 to 20, y is, independently
for each occurrence, an integer selected from 0 to 20, n is an
integer greater than or equal to 1, and R.sub.1 and R.sub.2 are
each an optionally substituted alkyl that is saturated or
unsaturated, and branched or unbranched, free acid estolide 104 may
be esterified by any suitable procedure known to those of skilled
in the art, such as acid-catalyzed reduction with alcohol 202, to
yield esterified estolide 204. Other exemplary methods may include
other types of Fischer esterification, such as those using Lewis
acid catalysts such as BF.sub.3.
[0128] In all of the foregoing examples, the compounds described
may be useful alone, as mixtures, or in combination with other
compounds, compositions, and/or materials.
[0129] Methods for obtaining the novel compounds described herein
will be apparent to those of ordinary skill in the art, suitable
procedures being described, for example, in the examples below, and
in the references cited herein.
EXAMPLES
Analytics
[0130] Nuclear Magnetic Resonance: NMR spectra were collected using
a Bruker Avance 500 spectrometer with an absolute frequency of
500.113 MHz at 300 K using CDCl.sub.3 as the solvent. Chemical
shifts were reported as parts per million from tetramethylsilane.
The formation of a secondary ester link between fatty acids,
indicating the formation of estolide, was verified with .sup.1H NMR
by a peak at about 4.84 ppm.
[0131] Estolide Number (EN): The EN was measured by GC analysis. It
should be understood that the EN of a composition specifically
refers to EN characteristics of any estolide compounds present in
the composition. Accordingly, an estolide composition having a
particular EN may also comprise other components, such as natural
or synthetic additives, other non-estolide base oils, fatty acid
esters, e.g., triglycerides, and/or fatty acids, but the EN as used
herein, unless otherwise indicated, refers to the value for the
estolide fraction of the estolide composition.
[0132] Iodine Value (IV): The iodine value is a measure of the
degree of total unsaturation of an oil. IV is expressed in terms of
centigrams of iodine absorbed per gram of oil sample. Therefore,
the higher the iodine value of an oil the higher the level of
unsaturation is of that oil. The IV may be measured and/or
estimated by GC analysis. Where a composition includes unsaturated
compounds other than estolides as set forth in Formula I, II, and
III, the estolides can be separated from other unsaturated
compounds present in the composition prior to measuring the iodine
value of the constituent estolides. For example, if a composition
includes unsaturated fatty acids or triglycerides comprising
unsaturated fatty acids, these can be separated from the estolides
present in the composition prior to measuring the iodine value for
the one or more estolides.
[0133] Acid Value: The acid value is a measure of the total acid
present in an oil. Acid value may be determined by any suitable
titration method known to those of ordinary skill in the art. For
example, acid values may be determined by the amount of KOH that is
required to neutralize a given sample of oil, and thus may be
expressed in terms of mg KOH/g of oil.
[0134] Gas Chromatography (GC): GC analysis was performed to
evaluate the estolide number (EN) and iodine value (IV) of the
estolides. This analysis was performed using an Agilent 6890N
series gas chromatograph equipped with a flame-ionization detector
and an autosampler/injector along with an SP-2380 30 m.times.0.25
mm i.d. column.
[0135] The parameters of the analysis were as follows: column flow
at 1.0 mL/min with a helium head pressure of 14.99 psi; split ratio
of 50:1; programmed ramp of 120-135.degree. C. at 20.degree.
C./min, 135-265.degree. C. at 7.degree. C./min, hold for 5 min at
265.degree. C.; injector and detector temperatures set at
250.degree. C.
[0136] Measuring EN and IV by GC: To perform these analyses, the
fatty acid components of an estolide sample were reacted with MeOH
to form fatty acid methyl esters by a method that left behind a
hydroxy group at sites where estolide links were once present.
Standards of fatty acid methyl esters were first analyzed to
establish elution times.
[0137] Sample Preparation: To prepare the samples, 10 mg of
estolide was combined with 0.5 mL of 0.5M KOH/MeOH in a vial and
heated at 100.degree. C. for 1 hour. This was followed by the
addition of 1.5 mL of 1.0 M H.sub.2SO.sub.4/MeOH and heated at
100.degree. C. for 15 minutes and then allowed to cool to room
temperature. One (1) mL of H.sub.2O and 1 mL of hexane were then
added to the vial and the resulting liquid phases were mixed
thoroughly. The layers were then allowed to phase separate for 1
minute. The bottom H.sub.2O layer was removed and discarded. A
small amount of drying agent (Na.sub.2SO.sub.4 anhydrous) was then
added to the organic layer after which the organic layer was then
transferred to a 2 mL crimp cap vial and analyzed.
[0138] EN Calculation: The EN is measured as the percent hydroxy
fatty acids divided by the percent non-hydroxy fatty acids. As an
example, a dimer estolide would result in half of the fatty acids
containing a hydroxy functional group, with the other half lacking
a hydroxyl functional group. Therefore, the EN would be 50% hydroxy
fatty acids divided by 50% non-hydroxy fatty acids, resulting in an
EN value of 1 that corresponds to the single estolide link between
the capping fatty acid and base fatty acid of the dimer.
[0139] IV Calculation: The iodine value is estimated by the
following equation based on ASTM Method D97 (ASTM International,
Conshohocken, Pa.):
IV = 100 .times. A f .times. MW I .times. db MW f ##EQU00001##
[0140] A.sub.f=fraction of fatty compound in the sample
[0141] MW.sub.I=253.81, atomic weight of two iodine atoms added to
a double bond
[0142] db=number of double bonds on the fatty compound
[0143] MW.sub.f=molecular weight of the fatty compound
[0144] The properties of exemplary estolide compounds and
compositions described herein are identified in the following
examples and tables.
[0145] Other Measurements: Except as otherwise described, pour
point is measured by ASTM Method D97-96a, cloud point is measured
by ASTM Method D2500, viscosity/kinematic viscosity is measured by
ASTM Method D445-97, viscosity index is measured by ASTM Method
D2270-93 (Reapproved 1998), specific gravity is measured by ASTM
Method D4052, flash point is measured by ASTM Method D92,
evaporative loss is measured by ASTM Method D5800, vapor pressure
is measured by ASTM Method D5191, and acute aqueous toxicity is
measured by Organization of Economic Cooperation and Development
(OECD) 203.
Example 1
[0146] The acid catalyst reaction was conducted in a 50 gallon
Pfaudler RT-Series glass-lined reactor. Oleic acid (65 Kg, OL 700,
Twin Rivers) was added to the reactor with 70% perchloric acid
(992.3 mL, Aldrich Cat#244252) and heated to 60.degree. C. in vacuo
(10 torr abs) for 24 hrs while continuously being agitated. After
24 hours the vacuum was released. 2-Ethylhexanol (29.97 Kg) was
then added to the reactor and the vacuum was restored. The reaction
was allowed to continue under the same conditions (60.degree. C.,
10 torr abs) for 4 more hours. At which time, KOH (645.58 g) was
dissolved in 90% ethanol/water (5000 mL, 90% EtOH by volume) and
added to the reactor to quench the acid. The solution was then
allowed to cool for approximately 30 minutes. The contents of the
reactor were then pumped through a 1 micron (.mu.) filter into an
accumulator to filter out the salts. Water was then added to the
accumulator to wash the oil. The two liquid phases were thoroughly
mixed together for approximately 1 hour. The solution was then
allowed to phase separate for approximately 30 minutes. The water
layer was drained and disposed of. The organic layer was again
pumped through a 1.mu. filter back into the reactor. The reactor
was heated to 60.degree. C. in vacuo (10 torr abs) until all
ethanol and water ceased to distill from solution. The reactor was
then heated to 100.degree. C. in vacuo (10 torr abs) and that
temperature was maintained until the 2-ethylhexanol ceased to
distill from solution. The remaining material was then distilled
using a Myers 15 Centrifugal Distillation still at 200.degree. C.
under an absolute pressure of approximately 12 microns (0.012 torr)
to remove all monoester material leaving behind estolides (Ex. 1).
Certain data are reported below in Tables 1 and 6.
Example 2
[0147] The acid catalyst reaction was conducted in a 50 gallon
Pfaudler RT-Series glass-lined reactor. Oleic acid (50 Kg, OL 700,
Twin Rivers) and whole cut coconut fatty acid (18.754 Kg, TRC 110,
Twin Rivers) were added to the reactor with 70% perchloric acid
(1145 mL, Aldrich Cat#244252) and heated to 60.degree. C. in vacuo
(10 torr abs) for 24 hrs while continuously being agitated. After
24 hours the vacuum was released. 2-Ethylhexanol (34.58 Kg) was
then added to the reactor and the vacuum was restored. The reaction
was allowed to continue under the same conditions (60.degree. C.,
10 torr abs) for 4 more hours. At which time, KOH (744.9 g) was
dissolved in 90% ethanol/water (5000 mL, 90% EtOH by volume) and
added to the reactor to quench the acid. The solution was then
allowed to cool for approximately 30 minutes. The contents of the
reactor were then pumped through a 1.mu. filter into an accumulator
to filter out the salts. Water was then added to the accumulator to
wash the oil. The two liquid phases were thoroughly mixed together
for approximately 1 hour. The solution was then allowed to phase
separate for approximately 30 minutes. The water layer was drained
and disposed of. The organic layer was again pumped through a 1.mu.
filter back into the reactor. The reactor was heated to 60.degree.
C. in vacuo (10 torr abs) until all ethanol and water ceased to
distill from solution. The reactor was then heated to 100.degree.
C. in vacuo (10 torr abs) and that temperature was maintained until
the 2-ethylhexanol ceased to distill from solution. The remaining
material was then distilled using a Myers 15 Centrifugal
Distillation still at 200.degree. C. under an absolute pressure of
approximately 12 microns (0.012 torr) to remove all monoester
material leaving behind estolides (Ex. 2). Certain data are
reported below in Tables 2 and 5.
Example 3
[0148] The estolides produced in Example 1 (Ex. 1) were subjected
to distillation conditions in a Myers 15 Centrifugal Distillation
still at 300.degree. C. under an absolute pressure of approximately
12 microns (0.012 torr). This resulted in a primary distillate
having a lower EN average (Ex. 3A), and a distillation residue
having a higher EN average (Ex. 3B). Certain data are reported
below in Tables 1 and 6.
TABLE-US-00001 TABLE 1 Pour Iodine Estolide Point Value Base Stock
EN (.degree. C.) (cg/g) Ex. 3A 1.35 -32 31.5 Ex. 1 2.34 -40 22.4
Ex. 3B 4.43 -40 13.8
Example 4
[0149] Estolides produced in Example 2 (Ex. 2) were subjected to
distillation conditions in a Myers 15 Centrifugal Distillation
still at 300.degree. C. under an absolute pressure of approximately
12 microns (0.012 torr). This resulted in a primary distillate
having a lower EN average (Ex. 4A), and a distillation residue
having a higher EN average (Ex. 4B). Certain data are reported
below in Tables 2 and 5.
TABLE-US-00002 TABLE 2 Estolide Iodine Base Stock EN Pour Point
(.degree. C.) Value (cg/g) Ex. 4A 1.31 -30 13.8 Ex. 2 1.82 -33 13.2
Ex. 4B 3.22 -36 9.0
Example 5
[0150] Estolides were made according to the method set forth in
Example 1, except that the 2-ethylhexanol esterifying alcohol used
in Example 1 was replaced with various other alcohols. Alcohols
used for esterification include those identified in Table 3 below.
The properties of the resulting estolides are set forth in Table
7.
TABLE-US-00003 TABLE 3 Alcohol Structure Jarcol .TM. I-18CG
iso-octadecanol Jarcol .TM. I-12 2-butyloctanol Jarcol .TM. I-20
2-octyldodecanol Jarcol .TM. I-16 2-hexyldecanol Jarcol .TM. 85BJ
cis-9-octadecen-1-ol Fineoxocol .RTM. 180 iso-stearyl alcohol
Jarcol .TM. I-18T 2-octyldecanol
Example 6
[0151] Estolides were made according to the method set forth in
Example 2, except the 2-ethylhexanol esterifying alcohol was
replaced with isobutanol. The properties of the resulting estolides
are set forth in Table 7.
Example 7
[0152] Estolides of Formula I, II, and III are prepared according
to the method set forth in Examples 1 and 2, except that the
2-ethylhexanol esterifying alcohol is replaced with various other
alcohols. Alcohols to be used for esterification include those
identified in Table 4 below. Esterifying alcohols to be used,
including those listed below, may be saturated or unsaturated, and
branched or unbranched, or substituted with one or more alkyl
groups selected from methyl, ethyl, propyl, isopropyl, butyl,
isobutyl, sec-butyl, tert-butyl, pentyl, isopentyl, neopentyl,
hexyl, isohexyl, and the like, to form a branched or unbranched
residue at the R.sub.2 position. Examples of combinations of
esterifying alcohols and R.sub.2 substituents are set forth below
in Table 4:
TABLE-US-00004 TABLE 4 Alcohol R.sub.2 Substituents C.sub.1 alkanol
methyl C.sub.2 alkanol ethyl C.sub.3 alkanol n-propyl, isopropyl
C.sub.4 alkanol n-butyl, isobutyl, sec-butyl C.sub.5 alkanol
n-pentyl, isopentyl neopentyl C.sub.6 alkanol n-hexyl, 2-methyl
pentyl, 3- methyl pentyl, 2,2-dimethyl butyl, 2,3-dimethyl butyl
C.sub.7 alkanol n-heptyl and other structural isomers C.sub.8
alkanol n-octyl and other structural isomers C.sub.9 alkanol
n-nonyl and other structural isomers C.sub.10 alkanol n-decanyl and
other structural isomers C.sub.11 alkanol n-undecanyl and other
structural isomers C.sub.12 alkanol n-dodecanyl and other
structural isomers C.sub.13 alkanol n-tridecanyl and other
structural isomers C.sub.14 alkanol n-tetradecanyl and other
structural isomers C.sub.15 alkanol n-pentadecanyl and other
structural isomers C.sub.16 alkanol n-hexadecanyl and other
structural isomers C.sub.17 alkanol n-heptadecanyl and other
structural isomers C.sub.18 alkanol n-octadecanyl and other
structural isomers C.sub.19 alkanol n-nonadecanyl and other
structural isomers C.sub.20 alkanol n-icosanyl and other structural
isomers C.sub.21 alkanol n-heneicosanyl and other structural
isomers C.sub.22 alkanol n-docosanyl and other structural
isomers
Example 8
[0153] Potato chip preparation: whole peeled potatoes are sliced,
washed in water, and fried in the estolide composition prepared
according to the method set forth in Example 4A. The Example 4A
cooking and frying oil is heated in a pan to 375.degree. F., to
which the sliced and washed potatoes are added. The potato chips
are cooked until a conventional light-brown color is achieved. The
excess oil is shaken off the fried potato chips and the chips are
then salted to taste.
Example 9
[0154] Cake frosting preparation: vanilla flavor (0.3 wt. %), salt
(0.5 wt. %), food colorants (Yellow #5, 0.02 wt. %; Red #40, 0.01
wt. %), microcrystalline cellulose (0.3 wt. %), preservatives
(microcrystalline cellulose, 0.3 wt. %; titanium dioxide, 0.27 wt.
%; potassium sorbate, 0.10 wt. %; citric acid, 0.02 wt. %) and
powdered sugar (57 wt. %) are blended for five minutes using a
Hobart paddle mixer at speed one. Ex. 3B estolides (20 wt. %) are
added next and blended for five minutes at speed one. In a smaller
Hobart paddle mixer, maltodextrin (7.15 wt. %) and polysorbate 80
(0.18 wt. %) are added to water (14.15 wt. %) and blended. This
solution or dispersion is then added slowly to the mixing bowl
containing the sugar/estolide blend while the paddle mixer is
operated at speed one. The water addition takes about one minute
and the combined ingredients are scraped down and blended at speed
one for one additional minute. After another scrapedown, the entire
mixture is whipped for five minutes at speed three.
* * * * *